作者:Ask Püschl、Thomas Boesen、Tullia Tedeschi、Otto Dahl、Peter E. Nielsen
DOI:10.1039/b103901f
日期:——
Two new conformationally restricted piperidinone PNA adenine monomers 12 and 13 have been synthesised using a stereoselective synthesis strategy analogous to a previously published strategy for pyrrolidinone analogues. In contrast to the pyrrolidinone case, epimerisation occurred during the final hydrolysis step. However, the diastereomeric mixture could be separated by RP-HPLC to give small amounts of pure 12 and 13. These were built into a PNA dodecamer (once in a central position), and the thermal stability (Tm) of the modified oligomers hybridised to complementary DNA, RNA and PNA were measured. PNA modified with either 12 or 13 resulted in a decrease of the Tm compared to unmodified PNA and to pyrrolidinone modified PNA. Thus, any preorganisation for duplex formation of PNA with a six-membered piperidinone ring seems to be inferior to preorganisation with a five-membered ring in the pyrrolidinone PNA analogues studied earlier.
我们采用立体选择性合成策略合成了两种新的构象受限的哌啶酮 PNA 腺嘌呤单体 12 和 13,该策略类似于之前发表的吡咯烷酮类似物的合成策略。与吡咯烷酮的情况不同的是,在最后的水解步骤中发生了二聚反应。不过,非对映异构体混合物可以通过 RP-HPLC 分离出来,得到少量纯的 12 和 13。将这些物质加入 PNA 十二聚体(一次位于中心位置),并测量了与互补 DNA、RNA 和 PNA 杂交的修饰寡聚体的热稳定性(Tm)。与未修饰的 PNA 和吡咯烷酮修饰的 PNA 相比,用 12 或 13 修饰的 PNA 会降低 Tm。因此,在先前研究的吡咯烷酮 PNA 类似物中,任何具有六元哌啶酮环的 PNA 双链形成预组织似乎都不如具有五元环的预组织。